Washing of laundry is an expensive process. It utilizes costly resources—water, energy, detergents and labor and such laundering is often required to disinfect the laundry items. While conventional detergents and soap can be effective in removing dirt, grease, grime and other contaminants, they are not always effective at killing germs and bacteria. It is known to enhance the disinfection capabilities of a washing machine by introducing ozone into the washing water. The ozone improves cleaning of laundry, at low wash water temperatures, and also has an antibacterial effect.
Previous systems for introducing ozone have included a simple bubble system in which ozone is bubbled through water in a washing machine drum. The efficiency of dissolving ozone in such apparatus is low, and the concentration of dissolved ozone in the water is consequently low thereby resulting in only a small enhancement in the cleaning and the antibacterial effect of the ozone. There is also the disadvantage that the amount of off-gas, i.e., the ozone given off to the surrounding environment during operation of the washing machine, can be considerable. The ozone gas will typically collect in the area surrounding the washing machine and can cause health and safety problems in the event that any person located adjacent the washing machine is exposed to a high concentration of ozone.
In order to improve the efficiency with which ozone is dissolved in the water, systems using venturis have been developed. Such systems forcibly dissolve ozone in the water and improve the concentration of dissolved ozone. However, these systems are complex and often require major changes to the plumbing or pipework of the washing machine in order to install such systems. In addition, further space is also required for the venturi itself and associated components, such as tanks and pumps.
Another problem associated with prior art washing machine having an ozone generating system is that there is no mechanism for controlling the amount of ozone generated during a wash cycle. As a result of this, a dangerous level of ozone can be generating during operation of the washing machine, especially at a laundry mat or a commercial laundry facility, thereby creating a situation which is hazardous to human beings.